Although powerful, those spectral filters are computationally complex and spatially not localized due to the forward and inverse GFT operations.
To reduce their complexity and make them localized, Chebyshev convolutional graph filters are proposed in [1]}.
Chebyshev polynomial of the first kind \(T_k(x)\)  with the order \(K\)  can be computed by a recursion as follows:
\( T_k(x) = 2x T_{k-1}(x) - T_{k-2}(x),\) 
